Control system for theater lighting circuits



Sept. 20, 1932. A. LE R. UPTON CONTROL SYSTEM FOR THEATER LIGHTING CIRCUITS 2 Sheets-Sheet Filed Oct. 20, 1930 Sept. 20, 1932. LE R UPTQN 1,878,304

CONTROL SYSTEM FOR THEATER LIGHTING CIRCUITS.

Filed Oct. 20, 1950 2 Sheets-Sheet 2 Patented Sept. 20. 1932 I UNITED STATES mnn'r LE not arrow,

or s'r. Lou s, ,mssomu CONTROL SYSTEM FOR THEATER LIGHTING GIRG' U-I'IS Application filed October 20, 1980. Serial No. 489,829.

This invention relates to a system for con: trolling electrical circuits for theater lighting, whereby the brilliancy of the lighting ina plurality of circuits may be selectively controlled.

One of the objects of this invention is to provide a system of controls which will be convenient and eflicient. 7

Another object of the invention is to pro vide a system whereby a number of circuits may be selected and each set to a selected maximum brilliancy and each of the circuits so selected may besimultaneously controlled by unitary means from black-out to the maximum brilliancy for which they are set.

Another object of the invention is to provide a plurality of lightin units, each controlled by a control. circuit with means to selectively connect a plurality of such control circuits to each of a plurality of master.

switches so'arranged that an individual circuit first connected in circuit by one master switch may not be subsequently connected in circuit by another master switch until released from the circuit controlled by the first master switch.

Another object of theinvention is to pro- .vide means for pre-selective dimming of theater lighting circuits; that is, to provide a plurality of dimming controls for each lighting unit, which controls may be set in advance of the performance and selectively put into service immediately by a unitary control.

Other and specific objects of the invention 1 will be apparent from the following detail description taken in connection with the accompanying drawings.

Fig. 1 is a circuit diagram of the system.

Fig. 2 is a circuit diagram of a part of the system showing a modification. v

A plurality of lighting units are provided in which the lamps are supplied with alter.- nating current, the current being regulated through a reactance unit by varying the voltage in a direct current circuit acting upon the reactance unit. The problems solved by this invention relate principally to means for varying the voltage of the direct current circuit which in turn affects the brilliancy of these lighting units are contemplated, for in many of the larger theaters the number of these circuit units exceeds one hundred. The two lighting circuit units illustrated may be designated, respectively, A and B. Each of theunits A and B are identical, and thusa single description will sufiice for both.

Lamps 1 are supplied with alternating current'through wires 2 and 3. The wire 2 is connected through a bar 4 of the relay 5 with a wire 6 which comprises one side of the alter nating current main. A reactance unit 7 includes alternating windings 8 and 9. One side of the winding 8 is connected to one end of a wire 10 which has its other end connected to one .side of the winding 9. The other side of the winding 8 is connected to the wire 3 and the other side of the winding 9 is connected to a wire 11, which is connected by a conductor bar 12 of the relay 5 to a wire 13 constituting with the wire 6 the alternating current mains.

The path then of the alternating current which supplies the lampsbf each lighting unit is as follows:

From the wire 6, one of the alternating current mains, through the conductor bar 4 of the relay 5, the wire 2, the lamps 1, the wire 3, the winding 8 of the reactance unit, the

from its combination with other elements of ings, more than two of such units will be required in ordinary practice, but since the method of adding the further units will be obvious the illustration of two units will be suflicient to illustrate and explain the invention.

The arrangement illustrated is intended to be such that any or all of a plurality of windings 14 of the reactance units may be connected simultaneously by any one of the master switches 15 to a series of current supply. Pre-selective switch units 17 are also provided, one for each lamp unit, by which the circuits may be set up on a switch board preparatory to the operation of the master switches.

The master switch includes an electrically conductive movable bar 18 and a series of contact members 19 movable with and electri cally connected'to the bar 18. Stationary terminals 20 in a number equal to the lamp units, or windings 14, are provided to engage the contact points 19 and these are, as illustrated in Fig. l, numbered specifically 20a and 206. A stationary terminal 21 is similarly provided to contact with a member 19 and is connected by a wire 22 to the positive side of an auxiliary generator 23. A stationary terminal 24 is also provided and is connected by a wire 25 to the positive side of thegener ator 16 which is apart of the unit to which the master switch belongs.

Each of the terminals 20 is connected by a wire 26 to a movable contact 27 of a switch unit 17. Thus, the terminal 20a is connected by a wire 26a to a movable contact 27 of the switch unit 17 of the lighting unit A, and the terminal 20?) is connected by a wire 26b to a. movable contact 27 of the switch 17 in the lighting unit B. It is obvious that as many terminals 20 will be provided for each master switch 15 as there are lighting units capable of control through such switch, and as many I movable contacts 27 will be provided on each pre-selective switch unit .17 as there are master switches intended to control the lamp unit to which the switch unit belongs.

The pre-selective switch unit 17 includes a bus bar 28 to which is secured stationary terminals 280, one for each m'ovable contact 27. An adjustable resistance 3t) is connected on one side to the bar 28 and on the other side to a. wire 29 leading to oneside of the winding '14. The other side of the winding 14 is connected by awire 31 to relay mechanism, which need not now be described, selectively to one aevaaoa In actual operation a movable contact 27 of each selected lamp unit is thrown so as to connect the bar 28 with a selected master switch 15. The master switch may then be thrown, thus connecting in parallel the windings 14 of the selected lamp units with a particular generator.

The path of the direct current from the generator through the winding 14 is as follows: From the positive pole of the generator 16 through the wire 25, stationary terminal 24, a contact member 19, bar 18, a contact member 19, wire 20, movable contact 27, terminal 280, bus bar 28, resistance 30, wire 29, winding 14, wire 31, relay unit and wire 32 to the negative pole of the generator 16.

An auxiliary source of direct current supply is provided which comprises the generator 23. The purpose of this additional source of supply is to provide a direct current of constant voltage to operate the several relays. As previously indicated, the

wire 22 is connected to the positive side ofv sponding master switch are closed, the path of the direct current for controlling the relay 5 is as follows: From the positive side of the generator 23 through the wire 22, terminal 21, a contact point 19, bar 18, terminal 20, wire 26, movable contact 27. terminal 280. bar 28, wire 35, to solenoid of relay 5, and

' wire 34 to the negative side of the auxiliary generator 23. I

The relay mechanism by which, as pre- ICC viously indicated, the wire 31 is connected to i a wire 32 will now be described. Identical relay mechanism is provided for each lightmg unit and a descr ption of one will sufiice for all. A relay 36 has a conductor 37 normally held against terminals 38, 39 and 40. by a spring 41, and is arranged in a circuit in such a way that when current is passing through the winding 14 of the same lighting unit, the bar 37 will move away from the terminals 38, 39 and 40.

Each lighting unithas a plurality of relavs 42, one for each available master switch 15. Each relay 42 has conductors 43 and 44insulated from each other, the conductor 43 being adapted to connect terminals 45 and '46, and the conductor 44 being adapted to other end connected to the terminal 46 of one of the relays 42. The terminal is similarly connected to one end of a. wire 50 which has its other end connected to a terminal 46 of the other relay 42 in the same lighting unit. One side of the solenoid of the relay 36 is connected by a; wire 51 to the terminal 47 of each of the relays 42. One side of the solenoid of-the relay 42 is connected to a wire 32 leading to the negative side of the generator to which it belongs, and, therefore, the solenoid of a relay is connected to the generatorto which it is appurtenant. The other side of the solenoid of each of the relays 42 is connected by the wire 49 (or 50) to the terminal 39 (or 40, as the ca'se maybe) and, therefore, to the terminal 46. The terminals 45 are connected to the wire 31, and the terminals 47 are connected to the wire'51. The terminal 48 is connected by a wire 52 to the positive side of 32 which is appropriate to the generator the positive side of which has been connected to the winding 14, and thus to the negative side of the generator. It will be'seen, therefore, that current in passing through the winding 14 and the wire 31 will serve to close only the relay 42 appropriate to the generator, the positive side of which has'been connected by the switches 15 and 27. The other relay,

or relays, 42 will remain open.

Upon operation of the relay 42 the bar 43 will connect the terminals 45 and 46, and the bar 44 will connect the terminals 47 and 48, with the following result: Current will flow from the positive side of the auxiliary generator 23 through the wire 52, terminal 48, conductor 44, terminal 47, wire 51, solenoid of relay 36, and wire 33 to the negative side of auxiliary generator 23, causing the relay 36 to break contact between the terminals 38, 39 and 40. Another current will flow from the wire 31 through terminal 45,

'conductor'43, terminal 46, solenoid of relay 42 to wire 32, thus providing a circuit to energize the relay 42 and maintain it closed until the circuit passin throu h the winding 14 has been opened. t is to e understood, however, that only the relay 42 appropriate to the energizing generator will e maintained closed, and since the relay 36 maintains the connection between, the terminals 38, 39 and 40 broken, it 'will be impossible to set up a circuit through the winding 14 cuit has been broken.

, It will also be seen that the system of re lays-42 serve to maintain the connection between one side of the source of current supply (through wire 31) with the other side of the same source of current supply only (through a wire 32) The path of that currentmay be traced as follows: From the wire 31 through terminal 45, conductor 43, terminal 46, wire 49 (or 50 but not through both), solenoid of a relay 42, to wire 32.

Each of the generators mayjbe supplied with a volt meter 53. As indicated in the drawings, each of the generators is compound wound, having a series winding-54 and a shunt winding 55. The'voltage supplied by the generator 23 may be adjusted by the resistance 56- in circuit with itsshuntwinding 55.

The voltage supplied by each of the other generators may be adjusted by a resistance 57 which is preferably a manually operable potentiometer. As shown in the drawings, an adjustable contact 58 of the potentiometer 57 is connected by the wire 59 to one side of the shunt windin 55. One end of the potentiometer wire 5 is connected by the wire 60 to the positive side of the generator and the other end is connected through a switch arm 61 and a wire 62 to the positive side of the generator in the adjustment as shown in the drawings. I desire to call the potentiometer 57 a master potentiometer because, as will presently appear, it is adapted to control simultaneously the brilliancy of a plurality of lighting units.

With this arrangement the voltage supplied by the generator may be manually adjusted at will through adjusting the field of the generator, and, it is possible thereby to manually control by a single means the voltage supplied to the several circuits which are connected to that generator. Thus, a number of lighting units may be connected through onemaster switch to one generator and the voltage of the direct current which influences those lighting units may be controlled by adjusting the potentiometer 57. The maximum brilliancy of an individual lighting unit may be fixed by adjusting the resistance 30 and the different lighting units,

y be variably adjusted. Thus, one circuit ay be adjusted to 40% brilliancy, a second circuit to 50%,brilliancy, and a third circuit to 60% brilliancy. All of the circuits may then be adjusted in-unison by a single means Y with the first series.

from their maximum brilliancy as controlled by their individual resistances to a black- 1 out stage and back again. This result, so

far as I am aware, has never been accomplished in any control system of'this kind.

It is desirable also to have a plurality of lighting units all connected so they may be simultaneously adjusted and at the same time have another set of circuits similarly c0'nnect ed which may be simultaneously adjusted To effect this result there has been provided a pair of grand master potentiometer sets 63 and 64: which include an individual potentiometer for each generator circuit, having their adjustable contacts mechanically connected so they may be moved in unison. As specifically shown in the drawings the movable contact members of the respective sets 63 and 64 are connected by a non-conductive bar. In ordinary practice,

' however, the contact members are supported by a radial arm secured to and rotatable by a shaft and the' mechanical connection mentioned is therefore accomplished by the simple expedient ofkeying the radial arms of each set to the same shaft. These are termed grand master potentiometers because they are adapted to simultaneously control. a plurality of generator units each supplying a plurality of control circuits. One side ofv each of the potentiometers in the sets 63 and 64, is connected'by a wire 65 to the positive side of its generator, and the other side is connected by a wire 66' to the negative side of its generator. The adjustable contacts of each of the potentiometers in the set 63 is connected by a wire 67 to a terminal 68 adapted to contact with the switch arm 61 of the potentiometer 57 in the same generator unit. Similarly the contact of each of the potentiometers inthe-set 64 is connected by a wire 69 to a terminal 7 0 adapted to contact with the switch'arm 61.

Circuits each controlling a series of lighting units may be transferred from the master potentiometers to a grand master potentiometer at either a black-out or full brilliancy stage. If the control circuits are atfull brilliancy stage the contacts of the potentiometers 57 will be in a position nearest a switch arm 61 so that no resistance is interposed between the contacts 58 and the switch arm 61. The grand master potentiometer is moved to full brilliancy situation and the switch arm 61 is moved to the appropriate contact 68 or 70. No interference with the control circuits will result from this transfer. If the lights are at a black-out stage the contact 58 willbe farthst away from the switch arm 6'1, thus interposing the maximum resistance'between the contact 58-and the switch arm 61. The grand master 'potentiometer will then be adjusted to run resistance ,position and the switch arm '61'inovedto its appropriate contact 68 or 70,

lighting units may be at the same time, by the set 64, adjusted from black-out to full brilliancy, and back again.

There is illustrated in Fig. 2 an embodiment which provides pre-selective dimming and also provides circuits whereby the relays are operated entirely by auxiliary current and are not in circuit with the dimming unit. With this arrangement each lamp unit may be set before the performance to its maximum brilliancy in accordance with the scenes to be displayed and thus avoid the necessity for setting each unit between the sizenes. I t

In the embodiment shown in Fig. 2 there is utilized lamp circuits and dimming units identical with'that illustrated in Fig. 1. The lamps 1 are supplied with alternating current through wires 2 and 3, the wire 2 being connected through a bar 4 of a relay 5 with the wire 6, and the wire 3 being connected in series with the windings 8 and 9 to the wire 11 which is connected through a bar 12 of the relay 5 to the wire 13. The

wires 6 and 13 constitute a source of alternating current supply as in the preceding diagram. The brilliancy of the lamps may be regulated by passin a direct current through a winding 9. s in the preceding figure, novelty res des in means for controlling passage ofdirect current through the winding 9 as well, ofcourse, as operating the relay 5. The path of the alternating current in this diagram is exactly the same as it is in the preceding figure.

A plurality of sources of direct current are provided for selectively feeding the Winding 14 of the lamp unit. It is to be understood, of course, that a plurality of lamp units are contemplated, although only one is shown in the drawings. The number of these lamp units depends upon the theater, and, as explained, lamp units may and do exceed one hundred in number. Because each unitis identically connected, only one unit need be shown, it being understood that the otherunits are connected and controlled in exactly the same manner. The units for supplying, direct current are designated I and II, and may include an individual generator for each unit with means for individually varying the Volta obtained from each source of supply. This last named means is not shown in- Fig. 2, it being understood that they may be included in the same man--.

ner as shown in Fig. 1.

Each source of supply includes a master switch 101. The arrangement is such that any lamp unit may be connected to any master switch. It is to be understood that while but two source of supply and two master switches are shown, ordinarily more than this number are required. Pre-selective switch units 102 are provided, one for each lamp unit, by which the circuits may be set up on a switchboard preparatory to the operation of the master switches.

The master switch includes a movable element comprisingintegrally a conductive bar- 103 and a conductive bar 104 separated by insulation 105. The bar 103 hasa series of contact members 19 movable with and electrically connected to the bar 103. Stationary terminals 20 in a number equal to the lamp units, or windings '14, are provided to engage, respectively, the contacts 19. A stationary terminal 24'is provided to contact with a member 19 and is connected by a wire 25 to the positive side of current.

Each of the terminals 20 is connected by a wire 26 to a contact 106 of a switch unit The bar 104 is adapted to accommodate the auxiliary current which operates the'relays. Stationary terminals 108, to the lamp units, are provided to engage contacts 107 on the 'bar 104, and a terminal 21 is similarly provided to engage a contact 107. The terminal 21 is connected by. a wire 22 to the positive .side of a source of auxiliary current. Each of the terminals 108 is connected by a wire 109 to a terminal 110 of a switch unit 102.

Each of the switch units 102 is provided with double blade switches 111, equal in number to the master switches, with which it may be connected; two being specifically shown in the drawings. The switch 111 includes .a blade 112 and a blade 113 arranged to beconnected, respectively, to the termi-' nals 114 and'115.

The arrangement is suchthat current will.

move from the source of supply through the "master switch, a wire 26, blade 112, and

through suitable connections to the winding 14 and then through suitable connections and a wire 32 to the negative side of the selected source of supply. These. connections will hereafter be described in detail.

The arrangement is such also. that the auxswitch blade 113, and then-through suitable connections to. the various relays and from the relays through suitable connections and va wire 33 to the negative sideof the source of auxiliary current. These connections, as

a source of direct.

ual in number.

well 'asthe relays, will hereafter be described 3 wire 122 to one side of the winding 14. The

other side of the winding 14 is connected by a wire 123 to a wire 124 leading to a terminal 125 on each of the relays 119. The terminal 125 is connected by a bar 126 to a terminal 127 which is connected to a wire 32.

It will thus be seen that when the circuits are closed the path of the direct current for the winding 14 will be: from the positive side of a source of direct current through a wire 25 to contact 24, through conductor bar 10.3, contact member 19, terminal 20, wire 26, terminal 106, switch blade112, terminal 114, p0.- tentiometer 11.6, .wire 117, terminal 118,. bar 120, terminal 121, wire 122, to one. side of the winding 14, thence from the winding through lay 119 isconnected by a'wire 128 to a ter-- minal 115. It will be understood that since there are a plurality of relays 119 in each lighting control unit, and the number of such relays corresponds to the number of master switches 101 provided, each relay will be connected by a separate wire 128 to a difierent terminal 115. The other side of the solenoid of the relay 119 is connected by a wire 129 to a terminal 130 of a relay. 131-. The terminal 130 is connected by a bar 132 to a terminal 133 which has attached wire" 134. The wire 134 is connected by a wire 135 to the wire 33 leading to the negative side of the source of auxiliary current supply. As many terminals 130 areprovided for the relay 131- as there are relays 119'. The construction of the relay 131 is'such that the bar 132 is normally in contact with the terminals and the terminal 133.

The path of the current, therefore, for thesolenoid of the relay 119 upon the initial closing of the circuit is as follows: from the positive side of the source of auxiliary current through the wire 22, terminal 21, contact 107, bar 104, terminal 108, wire 109, terminal 110,

' switch blade 113, terminal 115, wire 128 to one side of the solenoid otthe relay 119, thence through the wire 129, terminal 130, bar 132 of the relay 131, terminal 133, wire 13 1,,wire 135, and wire 33 to the negative side of the source of auxiliary current supply.

Upon closing of the relay 119, however, the path of the current thus described will be impossible, due to the fact that in a manner hereafter described the relay 131 will cause contact to be broken between the terminals 130 and terminal 133. A difl'erent path of current is, therefore, provided after the relay 119 is closed. The wire 129 leading to the solenoid of the relay 119 is connected by a wire 136 to a terminal 137 which is connected upon operation of the relay 119 by a bar 138 to a terminal 139. The terminal 139 is connected by a wire 140 to the wire 135, which is connected through the wire 33 to the negative side of the source of auxiliary current.

Upon closing the relay 119 the path of current is therefore as follows: from the auxiliary source of current supply through the path already described to the wire 128 to the solenoid of the relay 119, thence through wire 129, wire. 136, terminal 137, bar 138, terminal 139, wire 140, wire 135, and wire 33 to the negative side of the auxiliary source of current supply.

The relay 131 is also provided with a pair of terminals 141 which are connected by the bar 132 when the relay is operated due to current passing through its solenoid.

One side of the solenoid of therelay 131 is connected to a wire 142 which is connected to I a terminal 143 of the relay 119, and is adapted 142, through the solenoid of the relay 131 and through the wire 33 to the negative side of the auxiliary source of current supply. It will be observed that this circuit is controlled entirely by the operation of the relay 119.

The circuit for each lamp unit iscontrolled by the relay 5., One si'deof the solenoid of the relay 5 is connected by a wire 148 to the wire 147 which leads to the positive side of the auxiliary source of current supply. The

other side of the solenoid of the relay 5 is connected to a wire 149 which is connected to a terminal 141. The terminal 141 maybe connected by the bar 132 to its companion terminal 141, which is connected to wire 33 and thus to the negative side of the auxiliary source of current supply. The closing of this circuit and, therefore, the closing of the lamp circuit, is accomplished by the operation of i the relay131 connecting term nals 141.-

()ne side of each potentiometer 116 is connected to a terminal 114 and the other side is connected to the wire 124. The wire 124 is connected through the terminal 125, bar 126, and terminal 127 of the relay. 119 to the negative side of the source of current supply.

I may trace in detail the current from its source through the winding 14. It is as follows: from the positive side of the source of current supply 1 or II, through wire 25, terminal 24, contact 19, bar 103, terminal 20, wire 26, terminal 106, switch blade 112, terminal 114, potentiometer 116, wire 117, terminal 118, bar 120, terminal 121, wire 122, winding 14, wire 123, wire 124, terminal 125, bar 126, terminal 127, and wire 32 to the negative side of the source of current supply.

ore than one path similarly numbered is provided and the path taken depends upon the master switch 101 which is connected. The relays 119 are arranged in such a manner, however, as to prevent any connection with an unselected source of currentsupply and also to prevent current from one source being impressed upon the winding 14 while it is also receiving current from a difierent source.

It will be seen that a potentiometer 116 may be pre-set to give a certain maximum brilliancy to the light unit. It will be understood, as previously explained, that more than two master switches are ordinarily required, but for the sake of. explanation two will be sufficient. It may be assumed, for instance, that. there are to be two scenes, in one of them a particular lamp unit A should be set at 40% brilliancy, and in the other "scene at 60% brilliancy. The potentiometer 116 pertinent to master switch I may, therefore, be pre-set at 40% and the pertinent switch 111 may be pre-set. The other potentiometer which is pertinent to master switch 11 may be pre-set at 60% and the pertinent switch 111,;1nay be pre-set. When the cue comes for'lightingscene one, master switch I may be thrown and the lighting will be cared for. Similarly when the cue comes for lighting scene two, master switch II may be thrown.

When it is understood that a largenumber of lighting units must be operated for each scene, each calling for different settings, the

utility of the system just explained will be fully appreciated. With a switchboard of pr-opercapacity, with an adequate number of master switches, theentireswitchboarql may be set up preparatory to the performance so" that substantially all'of the'instant operath'rowing'the proper master switch. 'Vvhen taken in connection with themeans'for simultaneously dimming a set of currents, illustions requiredmay be performed by simply trated by" and explained in connection-with Fig. 1, it will be seen that a control system is provided which is efiicient-and convenient beyond that which is known and used at the present time.

It is to be understood that parts of the invention may be used without the whole, and that various changes may be made in the details of construction without departing from including a plurality of lighting units, sep' arate means for dimming each lighting unit, a plurality of direct current generators arranged to furnish efi'ective current to the lighting units, means for selectively varying the field of each generator whereby the voltage from the generator supplied to the lighting units may be varied at will, means whereby each of the lighting units may be selectively connected to any of the generators, and a master switch pertinent to each "of the generators arranged to simultaneously coni "a lighting unit, a circuit for afiectm the nect with the lighting units.

3. Apparatus of the character described including a plurality oflighting units, se

generator all of the selected arate means for. dimming each lighting unit,-

a plurality of direct current generators adapted to furnish efiective current for the lighting units, means for connecting any of said units to any of said generators, andmeans for simultaneously varying the field of a plurality of generators whereby the voltage from the generators supplied to the lighting units may be simultaneously varied at will.

4.. Apparatus of the character described 56 including a pluralityof lighting units, separate means for dimming each lighting unit, a plurality of direct current generators, arranged to furnish efiectiv' 'current to the lighting nnitsya resistance for the field of moved in unison for simultaneously varying each generator, and means whereby the resistances may bemechanically coupled and the field of the generators whereby the voltage from the generators supplied to the lighting units may be simultaneously varied at will.

' 5. Apparatus of the character described including a plurality of lighting units, separate means for dimming eachlighting unit, a plurality of direct current generators arranged to furnish effective current to the lighting units, means whereby any of the units'may be connected to any of the generators, a plurality 6f sets of resistances in the field arranged so that each set of resistances may vary the fields of a plurality of generators and thus each set of resistances vary the voltage supplied by the generators connected to said set at will.

6. In apparatus of the'character described a plurality of circuits, a plurality of sources of supply, each of said circuits having a sep- I arate lead for each source of supply, a switch in said lead and a resistance in said lead, and

a master switch for each source of supply whereby a plurality of selected circuits may be simultaneouslyconnected to a source of supply.

7. Apparatus of-the character described including a plurality of lighting units, a source of alternating current supp y for said lighting units, means under the influence of a direct current circuit for varying the brilliancy in each of the lightin units, means for selectively connecting a p urality of cir-' cuits to a plurality of sources of direct current supply, a master switch pertinent to each of said sources of supply whereby the plurality of said circuits ma besimultaneously connected to a source 0 supply, a relay pertinent to each lighting unit for controlling the alternating current circuit and connections under the influence of said master switch for operating said relay. I 8. In apparatus 0 the character described rent supply, separate leads connected to said a circuit and to one pole of the current supply,

a switch in eachof said leads, and a relay adapted to connect the circuit to the opposite '10s.

pole of the desired source of supply.

9111i apparatus of the character described alighting unit, a' circuit for afiectin'g the lighting unit, a plurality of sources 0 current supply for said circuit, a lead from said Y circuit to each of said sources of supply, a

pertinent to each source of suppl adapted to simultaneously connect a plura 'ty of such circuits to the sources. of supply, a source of auxiliary current for operating appropriate relays in said circuit, and means operable by the master switch for connecting said source of auxiliary current supply.

switch-in each of said leads, a master switch 10. In apparatus of the character described a plurality of lighting units,'a circuit for influencing each lighting unit, a plurality of sources of supply for said circuits, a separate lead from said circuit for each of said circuits to eachsource of supply, a switch in each lead, a resistance in each lead, and a master switch pertinent to each source of supply whereby a plurality of selected circuits may be ."simultaneously connected to the sources of. supply. I 11 In apparatus of the character described 1 iso a plurality of lighting units each including a circuit for influencing said lighting unit, a A plurality of sources of current supply for said circuits, a separate lead from each of said circuits to each of said sources of supply, a switch in said lead, a resistance in each of said leads, and means for varying the voltage of the sources of supply.

12. In apparatus of the character described 10 a plurality of lighting circuits, a circuit for influencing each of said lighting units, a plurality of direct current generators aiiording sources of supply for said circuits, a separate lead for each of said circuits to each of said generators, a switch in-each of said leads, a resistance in each of said leads, and means for varying the field of each of said generators whereby the voltage of the generator may be varied at will.

13. Apparatus of the character described including a plurality of lighting units, a i source of alternating current supply adapted 'to supply said lighting units, a reactance unit pertinent to and adapted to control the brilliancy of each lighting unit, a separable circuit for'impressing a direct current upon each of said reactance units, a source of direct current, a lead from each of said circuits, a switch in each of said leads, a resistance in rm each of said leads, a master switch adapted to connect all of said leads to said source of direct current, and means for controlling at will the voltage delivered by said source of direct current. x

a ALBERT LE ROY UPTON. 

